simplify.

1) 9 - 3 - 4
2) 9 + 1 +3
3) 6 + 1 + 3
4) 5 + 4 - 2
5) 6 - 5 + 2
6) 9 - 2 + 5

Help D:

Do the indicated procedures. For example:

10 - 3 + 2 = 9